Health Impact of Noise at Work

Workplace-related hearing loss is one of the most common industrial health issues. Workers can be exposed to dangerously high noise levels in environments such as construction sites, foundries or textile mills. The most publicized effect of noise at work is the loss of hearing, a medical problem observed among coppersmiths as early as 1731. Short-term exposure to excessive noise can cause temporary hearing loss, with the duration from a few seconds to a few days, while longer exposure can cause permanent hearing loss. Hearing loss that occurs over time is not always easy to identify, with workers themselves not realizing their hearing is becoming impaired. Apart from noise-induced hearing loss (NIHL), work-related noise has other negative health effects.

Noise-induced hearing loss

As the most common occupational disease in the developed world, NIHL accounts for about one-third of all work-related diseases, even ahead of skin and respiratory problems. It’s usually caused by prolonged exposure to loud noise. It’s recognized by the initial symptoms as the inability to hear high-pitched sounds. Unless the problem of excessive noise is addressed, the hearing will deteriorate further into an inability of hearing low-pitched sounds as well. Hearing loss can also occur without long-term exposure to noise. Short exposure to impulsive noises, sometimes even one strong impulse, such as an explosion or the operation of a nail or rivet gun can cause permanent effects, including loss of hearing and recurring tinnitus.

Hearing impairment

Hearing impairment can be caused by a mechanical blockage in the transmission of sound to the inner ear, also known as conductive hearing loss, or damage to the hair cells in the cochlea part of the inner ear, which is known as sensorineural hearing loss. In rare occasions, hearing impairment can be caused by central auditory processing disorders, when the auditory centres of the brain are damaged. Among workers, it’s not a rare case that a worker finds it embarrassing to tell the co-workers or employers about the hearing impairment. However, if untreated and undisclosed, hearing loss creates more problems for all parties than immediate action and openness would, even if at first it might seem hard to come out with the facts.

Ototoxic effects

When exposed to excessive noise, some dangerous substances can become ototoxic, literally ear-poisoning, while workers exposed to some of these substances and the loud noise seem to be at greater risk of hearing damage than those exposed to either noise or the substances separately. In these cases, individual hearing protection aids such as passive and active earmuffs are not an adequate solution. Instead, the employer needs to invest in quality environmental noise control solutions that eliminate or significantly reduce the noise at the source. The interaction between noise and chemicals has been particularly noted with some organic solvents that include toluene, styrene, and carbon disulphide. These solvents may appear in noisy environments such as paint and lacquer manufacturing, as well as plastics and printing industries.

Tinnitus

Described as a ringing, hissing or booming sensation in your ears, the risk of tinnitus increases with excessive exposure to noise. If the noise is impulsive, such as blasting or hammering, the risk rises substantially. Tinnitus is often the first sign that your hearing has been damaged by noise. According to an online British study carried out by the Royal National Institute for the Deaf, among almost 900 people with tinnitus, 42% believe that their tinnitus negatively impacts their performance at work. To make matters worse, 44% of the respondents failed to inform their employers or co-workers about their tinnitus, fearing that others wouldn’t understand the condition, while 23% kept their condition to themselves, fearing it may affect their future employment prospects.

Noise effects on pregnancy

Exposure of pregnant workers to high noise levels can affect the unborn child, while prolonged exposure of mothers may lead to increased blood pressure and tiredness. Experimental evidence shows that prolonged exposure of the unborn child to loud noise may impact later hearing, with low-frequency noise having greater potential for causing harm. It’s on the employers to assess the nature, degree, and duration of exposure of pregnant workers to noise, adjusting the working conditions where needed, in order to avoid the exposure of mothers. In this case, personal protective equipment also falls short of protecting the unborn child.

Occupational noise exposure can cause a variety of chronic health problems, aside from hearing loss. The way noise affects workers’ health depends on a complex mix of factors, however, it’s important to note that personal protective aids are not always an effective noise-cancelling solution, as seen in the example of ototoxicity and pregnant operators.